Rift Valley fever virus detection in susceptible hosts with special emphasis in insects.

Rift Valley fever phlebovirus (RVFV, Phenuiviridae) is an emerging arbovirus that can cause potentially fatal disease in many host species including ruminants and humans. Thus, tools to detect this pathogen within tissue samples from routine diagnostic investigations or for research purposes are of major interest. This study compares the immunohistological usefulness of several mono- and polyclonal antibodies against RVFV epitopes in tissue samples derived from natural hosts of epidemiologic importance (sheep), potentially virus transmitting insect species (Culex quinquefasciatus, Aedes aegypti) as well as scientific infection models (mouse, Drosophila melanogaster, C6/36 cell pellet). While the nucleoprotein was the epitope most prominently detected in mammal and mosquito tissue samples, fruit fly tissues showed expression of glycoproteins only. Antibodies against non-structural proteins exhibited single cell reactions in salivary glands of mosquitoes and the C6/36 cell pellet. However, as single antibodies exhibited a cross reactivity of varying degree in non-infected specimens, a careful interpretation of positive reactions and consideration of adequate controls remains of critical importance. The results suggest that primary antibodies directed against viral nucleoproteins and glycoproteins can facilitate RVFV detection in mammals and insects, respectively, and therefore will allow RVFV detection for diagnostic and research purposes.

Parenting styles, adolescents' attributions, and educational outcomes in nine heterogeneous high schools.

This article examined the contemporaneous and predictive relations between parenting styles, adolescents' attributions, and 4 educational outcomes. Data were collected from adolescents attending 6 high schools in California and 3 high schools in Wisconsin during the 1987-1988 and 1988-1989 school years. The results of path analyses partially confirmed the central hypotheses. Adolescents who perceived their parents as being nonauthoritative were more likely than their peers to attribute achievement outcomes to external causes or to low ability. Furthermore, the higher the proportion of dysfunctional attributions made for academic successes and failures, the lower the levels of classroom engagement and homework 1 year later. Although adolescents' attributional style provided a bridge between parenting style and 2 educational outcomes, it did not fully explain the impact of parenting on those outcomes. Additional analyses within gender and ethnic subgroups reinforced the overall pattern of findings observed within the entire sample.

The social structure of schooling.

The term social structure refers to a relatively enduring pattern of social arrangements or interrelations within a particular society, organization, or group. This chapter reviews how the social structure of the larger society and the organizational structure of schools affect the educational process within American schools. The institutional context of schooling is first discussed. The ideology of mass education, social stratification, status attainment, credentialism, and the emphasis on ability differences are considered. The focus then shifts to the organizational structure of schools, beginning with a discussion of the external social context for school organization. Attention is given to professionalism and bureaucracy, institutional forms of organization, decentralized control, and community influences. Finally, the internal structure of school organization is considered: teachers' working conditions, status differences among students, and curriculum tracking. Throughout, the emphasis is on ways in which social structure influences what is taught in school, how it is taught, and what is learned.

Over-time changes in adjustment and competence among adolescents from authoritative, authoritarian, indulgent, and neglectful families.

In a previous report, we demonstrated that adolescents' adjustment varies as a function of their parents' style (e.g., authoritative, authoritarian, indulgent, neglectful). This 1-year follow-up was conducted in order to examine whether the observed differences are maintained over time. In 1987, an ethnically and socioeconomically heterogeneous sample of approximately 2,300 14-18-year-olds provided information used to classify the adolescents' families into 1 of 4 parenting style groups. That year, and again 1 year later, the students completed a battery of standardized instruments tapping psychosocial development, school achievement, internalized distress, and behavior problems. Differences in adjustment associated with variations in parenting are either maintained or increase over time. However, whereas the benefits of authoritative parenting are largely in the maintenance of previous levels of high adjustment, the deleterious consequences of neglectful parenting continue to accumulate.

Impact of parenting practices on adolescent achievement: authoritative parenting, school involvement, and encouragement to succeed.

This article examines the impact of authoritative parenting, parental involvement in schooling, and parental encouragement to succeed on adolescent school achievement in an ethnically and socio-economically heterogeneous sample of approximately 6,400 American 14-18-year-olds. Adolescents reported in 1987 on their parents' general child-rearing practices and on their parents' achievement-specific socialization behaviors. In 1987, and again in 1988, data were collected on several aspects of the adolescents' school performance and school engagement. Authoritative parenting (high acceptance, supervision, and psychological autonomy granting) leads to better adolescent school performance and stronger school engagement. The positive impact of authoritative parenting on adolescent achievement, however, is mediated by the positive effect of authoritativeness on parental involvement in schooling. In addition, nonauthoritativeness attenuates the beneficial impact of parental involvement in schooling on adolescents achievement. Parental involvement is much more likely to promote adolescent school success when it occurs in the context of an authoritative home environment.

Ethnic differences in adolescent achievement. An ecological perspective.

Using data collected from a large sample of high school students, the authors challenge three widely held explanations for the superior school performance of Asian-American adolescents, and the inferior performance of African- and Hispanic-American adolescents: group differences in (a) parenting practices, (b) familial values about education, and (c) youngsters' beliefs about the occupational rewards of academic success. They found that White youngsters benefit from the combination of authoritative parenting and peer support for achievement, whereas Hispanic youngsters suffer from a combination of parental authoritarianism and low peer support. Among Asian-American students, peer support for academic excellence offsets the negative consequences of authoritarian parenting. Among African-American youngsters, the absence of peer support for achievement undermines the positive influence of authoritative parenting.

Caught between parents: adolescents' experience in divorced homes.

This study examined adolescents' feelings of being caught between parents to see whether this construct helps to explain (1) variability in their postdivorce adjustment and (2) associations between family/child characteristics and adolescent adjustment. Adolescents 10 to 18 years old (N = 522) were interviewed by telephone 4 1/2 years after their parents' separation. Feeling caught between parents was related to high parental conflict and hostility and low parental cooperation. Being close to both parents was associated with low feelings of being caught. The relation between time spent with each parent and feeling caught depended on the coparenting relationship. Adolescents in dual residence were especially likely to feel caught when parents were in high conflict, and especially unlikely to feel caught when parents cooperated. Feeling caught was related to poor adjustment outcomes. Parental conflict was only related to adjustment outcomes indirectly, through adolescents' feelings of being caught.

Patterns of competence and adjustment among adolescents from authoritative, authoritarian, indulgent, and neglectful families.

In order to test Maccoby and Martin's revision of Baumrind's conceptual framework, the families of approximately 4,100 14-18-year-olds were classified into 1 of 4 groups (authoritative, authoritarian, indulgent, or neglectful) on the basis of the adolescents' ratings of their parents on 2 dimensions: acceptance/involvement and strictness/supervision. The youngsters were then contrasted along 4 sets of outcomes: psychosocial development, school achievement, internalized distress, and problem behavior. Results indicate that adolescents who characterize their parents as authoritative score highest on measures of psychosocial competence and lowest on measures of psychological and behavioral dysfunction; the reverse is true for adolescents who describe their parents as neglectful. Adolescents whose parents are characterized as authoritarian score reasonably well on measures indexing obedience and conformity to the standards of adults but have relatively poorer self-conceptions than other youngsters. In contrast, adolescents from indulgent homes evidence a strong sense of self-confidence but report a higher frequency of substance abuse and school misconduct and are less engaged in school. The results provide support for Maccoby and Martin's framework and indicate the need to distinguish between two types of "permissive" families: those that are indulgent and those that are neglectful.

Standardized percentile curves of body-mass index for children and adolescents.

Weight-for-height indexes are often used in the clinical assessment of obesity in children and adolescents. The direct measurement of adiposity, using hydrostatic weighing and other techniques, is not feasible in studies involving young children or with large numbers of older subjects. Ratios of weight relative to height, such as the body-mass index (weight/height), may be used as indirect measures of obesity and correlate with more direct measures of adiposity. Using data from the First National Health and Nutrition Examination Study, 1971 to 1974, standardized percentile curves of body-mass index for white children and adolescents were developed. These curves may be used to monitor the body-mass index of white children and adolescents longitudinally and for comparing an individual with others of the same sex and age.

The relation of parenting style to adolescent school performance.

This article develops and tests a reformation of Baumrind's typology of authoritarian, permissive, and authoritative parenting styles in the context of adolescent school performance. Using a large and diverse sample of San Francisco Bay Area high school students (N = 7,836), we found that both authoritarian and permissive parenting styles were negatively associated with grades, and authoritative parenting was positively associated with grades. Parenting styles generally showed the expected relation to grades across gender, age, parental education, ethnic, and family structure categories. Authoritarian parenting tended to have a stronger association with grades than did the other 2 parenting styles, except among Hispanic males. The full typology best predicted grades among white students. Pure authoritative families (high on authoritative but not high on the other 2 indices) had the highest mean grades, while inconsistent families that combine authoritarian parenting with other parenting styles had the lowest grades.

Growth and intellectual development.

Data from the National Health Examination Survey (cycles II and III) provided a representative sample of 13,887 US youths (6 to 17 years of age) with which to examine the relationship between height (normalized for age and sex) and measures of intellectual development (Wechsler Intelligence Scale for Children) and academic achievement (Wide Range Achievement Test). Additionally, 2,177 subjects were studied first in cycle II and 2 to 5 years later in cycle III, forming a well-selected longitudinal study group in which to examine any association between linear growth and change in IQ scores. Wechsler Intelligence Scale for Children and Wide Range Achievement Test scores were significantly correlated with height in both cycle II and cycle III. However, no significant association between change in relative height and change in IQ scores could be detected in the longitudinal group. These data suggest that therapies designed to increase height are unlikely to alter measures of intellectual development or academic achievement.

Single parents, extended households, and the control of adolescents.

This paper uses a representative national sample of adolescents to study the interrelationships among family structure, patterns of family decision making, and deviant behavior among adolescents. Mother-only households are shown to be associated with particular patterns of family decision making and adolescent deviance, even when family income and parental education are controlled. In contrast to adolescents in households with 2 natural parents, youth in mother-only households are perceived as more likely to make decisions without direct parental input and more likely to exhibit deviant behavior. The presence of an additional adult in a mother-only household, especially for males, is associated with increased parental control and a reduction in various forms of adolescent deviance. Finally, patterns of family decision making and family structure both make independent contributions to adolescent deviance, and the impact of family structure on deviance of adolescent males is hardly affected by controlling for patterns of family decision making.

The effects of pubertal timing on body image, school behavior, and deviance.

Variation in the timing of pubertal maturation may result in behavioral differences among early, mid-, and late maturers. Using data from the National Health Examination Survey, a national probability sample of children and youth aged 12-17, we investigated the relationships between maturational timing and body image, school behavior, and deviance. In terms of body image, the early maturing boys were the group most satisfied with height and weight. The early maturing girls were most dissatisfied with weight, with 69% wishing to be thinner. This great dissatisfaction with weight reported by early maturing girls is probably not an affect of early maturation, but a concomitant of maturation in general. The majority of girls became dissatisfied with their weight as they matured, and females from the higher social groups were more likely to want to be thinner than females from lower groups. Thus, a normal developmental process is being viewed negatively by females and positively by males. Male early maturers more often had deviant behavior, but there were no consistent findings for girls. There was no effect of maturational timing on teacher reports of school absence, adjustment, popularity, need for discipline, or grade repetition.

Sexual maturation, social class, and the desire to be thin among adolescent females.

Veblen's 1899 hypothesis that associated a female desire for thinness with the higher social classes was tested with data from a representative national sample of adolescents, 12 to 17 years of age, in the National Health Examination Survey. Controlling for the actual level of fatness, adolescent females in higher social classes wanted to be thinner more often than those in lower classes. The greater female desire for thinness was not the product of health information nor of sex differences in the level of fatness. The thinner the female, the greater the impact of social class on the desire for thinness. During puberty, adolescent females negatively evaluated the body fat associated with normal sexual development.

Theory and observation in cultural transmission.

Cultural phenomena may show considerable stability over time and space. Transmission mechanisms responsible for their maintenance are worthy of theoretical and empirical inquiry; they are complex and each possible pathway has different effects on evolutionary stability of traits, as can be shown theoretically. A survey designed to evaluate the importance of some components of cultural transmission on a variety of traits showed that religion and politics are mostly determined in the family, a mode of transmission which guarantees high evolutionary stability and maintenance of high variation between and within groups.

Educational correlates of early and late sexual maturation in adolescence.

From the National Health Examination Survey data, 4,735 Caucasian males and females, 12 to 17 years, were classified by age and stage of sexual maturation (Tanner). Early and late maturers were each compared to all other youth of comparable age and sex, in eight education-related categories: youth and parental aspirations and expectations concerning the level of education which would be achieved by the student, teacher reports of intellectual ability and academic achievement, and test scores (WISC and WRAT). Except at age 12, late maturing boys received significantly lower ratings than mid maturers in all these areas, and early maturing males received higher ratings. For females, no differences persisted across age groups. In advising male adolescents, physicians should be alert to the possibility that school functioning may be linked to maturational processes.

Sexual development, age, and dating: a comparison of biological and social influences upon one set of behaviors.

Data from the U.S. National Health Examination Survey of 12-17-year-old youths were used to determine whether the development of the social behavior of dating is more closely linked to the level of sexual maturation or to the progression through age grades without reference to sexual maturation. Regression analyses and partial correlations show that individuals levels of sexual maturation add very little to the explained variance in dating after age had been taken into account. It appears that social pressures, based on behavior considered typical and appropriate at various ages, determines the onset of dating in adolescents. Individual rates of sexual maturation that deviate from the norm for that age have little impact on dating. These findings show how social standards can reduce dramatically the impact of individual biological processes on institutionalized forms of behavior.